Description: The experiments proposed will eludicate the mechanism of blindness in glaucoma, the second most common cause of vision loss in the world. An experimental model in rats will be used to study the hypothesis that retinal ganglion cell death occurs by apoptosis. The steps leading to cell death will be related to obstruction of axonal transport at the optic nerve head. The prevention of cell death will be studied using treatment with neurotrophic factors and insertion of gene sequences with viral vectors. A transgenic mouse model system will be used to investigate ganglion cell survival with alterations in genes related to apoptosis. The damage caused by glaucoma will be studied in human eyes that suffered glaucoma during the life of eye bank donors. The clinical features of visual loss in automated perimetry will be correlated with the numbrer and type of ganglion cells killed by glaucoma. The effect of glaucoma on the blue/yellow color perception system will be investigated. The participation of fibrillin, elastin, and collagen in axonal damage in glaucoma will be studied.